Issued: 2:51 PM PST Monday, December 11, 2023
by Robert Hahn

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I Extended Weather

Weather Synopsis

Forecast updated at 2:50 PM for cloud cover.

Benign weather continues throughout the first half of the work week. Most of the region experienced full sunshine by Monday afternoon. Clear skies continue overnight as an expanding offshore ridge inhibits cloud development (except for patchy valley fog). Temperatures warm to the west of the Cascade Crest Monday night and Tuesday. By Tuesday night, most areas can expect 7000 ft temperatures to rise above freezing. Contrasts are more dramatic at 3000 and 5000 ft elevations, where the Cascades effectively divide warm and cold air. A cold air pool continues to strengthen with time. Expect a low stratus deck around 3000-4500 ft to thicken as pressure gradients driving increasing E flow through the mountain gaps slosh the cold air up against the Cascades. By Tuesday, places like Snoqualmie and White Passes could experience moderate winds in exposed areas through the gaps along and may only briefly experience above-freezing temperatures during the mid-day hours.

A weakening approaching front brings increasing high and mid-level clouds to the region on Wednesday as freezing levels peak to the west of the Cascade Crest. By Wednesday afternoon, some light precipitation is possible in the Olympic Mountains.

 

Weather Forecast

Olympics
West North
West Central
West South
Stevens Pass
Snoqualmie Pass
East North
East Central
East South
Mt. Hood
Use dropdown to select your zone
Monday Night Mostly clear. Light ridgeline winds.
Tuesday Sunny and mild with filtered sunshine at times. Light ridgeline winds.
Monday Night Mostly clear. Light ridgeline winds.
Tuesday Sunny and mild with a few wispy high clouds. Light ridgeline winds.
Monday Night Mostly clear. Light ridgeline winds.
Tuesday Sunny with a few wispy high clouds. Light ridgeline winds (moderate winds at times close to the Cascade Crest).
Monday Night Mostly clear. Light ridgeline winds.
Tuesday Sunny and mild with a few wispy high clouds. Light ridgeline winds (moderate winds at times close to the Cascade Crest).
Monday Night Mostly clear with low stratus likely below 4500 ft. Light ridgeline winds and increasing light E winds at the Pass.
Tuesday Sunny and mild with a few wispy high clouds and low stratus lingering below 4500 ft. Increasing light to occasionally moderate ridgeline winds. Light E winds at the Pass.
Monday Night Mostly clear with low stratus developing below 4500 ft. Light to moderate ridgeline winds and light to moderate E winds at the Pass.
Tuesday Sunny and mild with a few wispy high clouds and low stratus likely below 4500 ft. Light to moderate ridgeline and E winds at the Pass, becoming steadily moderate.
Monday Night Mostly clear with low stratus developing below 4500 ft. Light ridgeline winds.
Tuesday Sunny and mild with a few wispy high clouds and low stratus likely below 4500 ft. Light ridgeline winds.
Monday Night Mostly clear with low stratus developing below 4500 ft. Light ridgeline winds.
Tuesday Sunny and mild with a few wispy high clouds and low stratus likely below 4500 ft. Mostly light ridgeline winds.
Monday Night Mostly clear with low stratus developing below 4500 ft. Light ridgeline winds.
Tuesday Sunny and mild with a few wispy high clouds and low stratus likely below 4500 ft. Mostly light ridgeline winds.
Monday Night Mostly clear. Light ridgeline winds.
Tuesday Sunny and mild with a few wispy high clouds. Mostly light ridgeline winds.

Issued: 2:51 PM PST Monday, December 11, 2023

Precipitation (in)

Monday Night Tuesday Tuesday Night Wednesday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0 0 0 LT 0.10
Mt Baker Ski Area 0 0 0 0
Mt. Loop - Barlow Pass 0 0 0 0
Stevens Pass 0 0 0 0
Snoqualmie Pass 0 0 0 0
Crystal Mt 0 0 0 0
Paradise 0 0 0 0
White Pass 0 0 0 0
Washington Pass 0 0 0 0
Mission Ridge 0 0 0 0
Salmon la Sac - Gallagher Head 0 0 0 0
Tieton River - Darland Mt. 0 0 0 0
Mt Hood Meadows 0 0 0 0
Timberline 0 0 0 0
Hurricane Ridge Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday LT 0.10
Mt Baker Ski Area Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Mt. Loop - Barlow Pass Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Stevens Pass Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Snoqualmie Pass Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Crystal Mt Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Paradise Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
White Pass Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Washington Pass Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Mission Ridge Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Tieton River - Darland Mt. Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Mt Hood Meadows Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0
Timberline Precipitation (in)
Monday Night 0
Tuesday 0
Tuesday Night 0
Wednesday 0

Issued: 2:51 PM PST Monday, December 11, 2023

Snow Level (ft)

Monday Evening* Monday Night* Tuesday Morning* Tuesday Afternoon* Tuesday Evening* Tuesday Night* Wednesday Morning* Wednesday Afternoon*
Olympics 5000' 5000' 5500' 9000' 9500' 9500' 10000' 8000'
West North 4500' 4000' 4500' 7500' 7000' 6500' 7000' 8000'
West Central 4500' 4000' 3500' 7000' 5500' 5000' 5000' 7000'
West South 4500' 3000' 3000' 6500' 5500' 5000' 5000' 9000'
Stevens Pass 4500' 3500' 2500' 4000' 4000' 3000' 4500' 6000'
Snoqualmie Pass 4500' 3500' 3000' 6000' 5500' 3000' 5000' 7000'
East North 4000' 3000' 2000' 4000' 3500' 1000' 4500' 5500'
East Central 4500' 3500' 3000' 4000' 4000' 1000' 4500' 6000'
East South 4500' 3500' 3000' 4500' 5000' 1500' 5000' 6500'
Mt. Hood 5500' 5000' 4500' 6000' 6500' 6500' 6500' 8500'
Olympics Elevation
Monday Evening* 5000'
Monday Night* 5000'
Tuesday Morning* 5500'
Tuesday Afternoon* 9000'
Tuesday Evening* 9500'
Tuesday Night* 9500'
Wednesday Morning* 10000'
Wednesday Afternoon* 8000'
West North Elevation
Monday Evening* 4500'
Monday Night* 4000'
Tuesday Morning* 4500'
Tuesday Afternoon* 7500'
Tuesday Evening* 7000'
Tuesday Night* 6500'
Wednesday Morning* 7000'
Wednesday Afternoon* 8000'
West Central Elevation
Monday Evening* 4500'
Monday Night* 4000'
Tuesday Morning* 3500'
Tuesday Afternoon* 7000'
Tuesday Evening* 5500'
Tuesday Night* 5000'
Wednesday Morning* 5000'
Wednesday Afternoon* 7000'
West South Elevation
Monday Evening* 4500'
Monday Night* 3000'
Tuesday Morning* 3000'
Tuesday Afternoon* 6500'
Tuesday Evening* 5500'
Tuesday Night* 5000'
Wednesday Morning* 5000'
Wednesday Afternoon* 9000'
Stevens Pass Elevation
Monday Evening* 4500'
Monday Night* 3500'
Tuesday Morning* 2500'
Tuesday Afternoon* 4000'
Tuesday Evening* 4000'
Tuesday Night* 3000'
Wednesday Morning* 4500'
Wednesday Afternoon* 6000'
Snoqualmie Pass Elevation
Monday Evening* 4500'
Monday Night* 3500'
Tuesday Morning* 3000'
Tuesday Afternoon* 6000'
Tuesday Evening* 5500'
Tuesday Night* 3000'
Wednesday Morning* 5000'
Wednesday Afternoon* 7000'
East North Elevation
Monday Evening* 4000'
Monday Night* 3000'
Tuesday Morning* 2000'
Tuesday Afternoon* 4000'
Tuesday Evening* 3500'
Tuesday Night* 1000'
Wednesday Morning* 4500'
Wednesday Afternoon* 5500'
East Central Elevation
Monday Evening* 4500'
Monday Night* 3500'
Tuesday Morning* 3000'
Tuesday Afternoon* 4000'
Tuesday Evening* 4000'
Tuesday Night* 1000'
Wednesday Morning* 4500'
Wednesday Afternoon* 6000'
East South Elevation
Monday Evening* 4500'
Monday Night* 3500'
Tuesday Morning* 3000'
Tuesday Afternoon* 4500'
Tuesday Evening* 5000'
Tuesday Night* 1500'
Wednesday Morning* 5000'
Wednesday Afternoon* 6500'
Mt. Hood Elevation
Monday Evening* 5500'
Monday Night* 5000'
Tuesday Morning* 4500'
Tuesday Afternoon* 6000'
Tuesday Evening* 6500'
Tuesday Night* 6500'
Wednesday Morning* 6500'
Wednesday Afternoon* 8500'

Issued: 2:51 PM PST Monday, December 11, 2023

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 31 / 29 39 / 30
West North 31 / 29 36 / 30
West Central 31 / 29 33 / 29
West South 30 / 28 35 / 28
Stevens Pass 28 / 24 28 / 24
Snoqualmie Pass 28 / 27 29 / 25
East North 26 / 23 26 / 20
East Central 27 / 24 28 / 22
East South 30 / 25 28 / 23
Mt. Hood 34 / 28 32 / 28
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 29
Tuesday 39 / 30
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 29
Tuesday 36 / 30
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 29
Tuesday 33 / 29
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 30 / 28
Tuesday 35 / 28
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 28 / 24
Tuesday 28 / 24
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 28 / 27
Tuesday 29 / 25
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 26 / 23
Tuesday 26 / 20
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 27 / 24
Tuesday 28 / 22
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 30 / 25
Tuesday 28 / 23
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 28
Tuesday 32 / 28

Issued: 2:51 PM PST Monday, December 11, 2023

Ridgeline Winds (mph)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics SSE 0-10 S 0-10 S 5-15 S 5-15
West North SSW 0-10 S 0-10 S 0-10 S 5-15
West Central ESE 0-10 SE 0-10 SE 5-15 SE 10-20
West South SE 0-10 SE 0-10 SE 0-10 SE 0-10
Stevens Pass ESE 5-15 ESE 0-10 SE 5-15 SE 5-15
Snoqualmie Pass ESE 5-15 ESE 10-20 ESE 10-20 ESE 10-20
East North NE 0-10 SSE 0-10 SSE 0-10 S 5-15
East Central E 0-10 ESE 0-10 SE 0-10 S 5-15
East South ESE 0-10 ESE 0-10 SE 5-15 SSE 5-15
Mt. Hood SSE 0-10 SSE 0-10 S 0-10 SSW 5-15
Olympics Ridgeline Winds (mph)
Monday Evening SSE 0-10
Monday Night S 0-10
Tuesday Morning S 5-15
Tuesday Afternoon S 5-15
West North Ridgeline Winds (mph)
Monday Evening SSW 0-10
Monday Night S 0-10
Tuesday Morning S 0-10
Tuesday Afternoon S 5-15
West Central Ridgeline Winds (mph)
Monday Evening ESE 0-10
Monday Night SE 0-10
Tuesday Morning SE 5-15
Tuesday Afternoon SE 10-20
West South Ridgeline Winds (mph)
Monday Evening SE 0-10
Monday Night SE 0-10
Tuesday Morning SE 0-10
Tuesday Afternoon SE 0-10
Stevens Pass Ridgeline Winds (mph)
Monday Evening ESE 5-15
Monday Night ESE 0-10
Tuesday Morning SE 5-15
Tuesday Afternoon SE 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Monday Evening ESE 5-15
Monday Night ESE 10-20
Tuesday Morning ESE 10-20
Tuesday Afternoon ESE 10-20
East North Ridgeline Winds (mph)
Monday Evening NE 0-10
Monday Night SSE 0-10
Tuesday Morning SSE 0-10
Tuesday Afternoon S 5-15
East Central Ridgeline Winds (mph)
Monday Evening E 0-10
Monday Night ESE 0-10
Tuesday Morning SE 0-10
Tuesday Afternoon S 5-15
East South Ridgeline Winds (mph)
Monday Evening ESE 0-10
Monday Night ESE 0-10
Tuesday Morning SE 5-15
Tuesday Afternoon SSE 5-15
Mt. Hood Ridgeline Winds (mph)
Monday Evening SSE 0-10
Monday Night SSE 0-10
Tuesday Morning S 0-10
Tuesday Afternoon SSW 5-15

Issued: 2:51 PM PST Monday, December 11, 2023

Extended Weather Synopsis

The weakening frontal system reaches the coast Wednesday by Wednesday evening. Mostly light amounts of rain and snow focus on the Olympics and Washington Cascades into Wednesday evening. Snow levels lower quickly as moisture moves into the dry air mass, ranging form 3000-4000 ft in the north to around 5000 ft in the southern Washington Cascades. Easterly flow weakens but should help keep the passes all snow. A broad ridge re-develops over the western US late Thursday and expands on Friday, elevating freezing levels while E flow keeps favored areas cool.

Extended Snow Level (ft)

Wednesday Night* Thursday * Thursday Night* Friday *
West North 4500' 3000' 3500' 5500'
Snoqualmie Pass 3000' 4000' 3000' 4000'
Mt. Hood 8500' 8000' 8000' 6500'
West North Elevation
Wednesday Night* 4500'
Thursday * 3000'
Thursday Night* 3500'
Friday * 5500'
Snoqualmie Pass Elevation
Wednesday Night* 3000'
Thursday * 4000'
Thursday Night* 3000'
Friday * 4000'
Mt. Hood Elevation
Wednesday Night* 8500'
Thursday * 8000'
Thursday Night* 8000'
Friday * 6500'

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I Extended Weather

Previous forecast from Dec 11, 2023

The NWAC program is administered by the USDA-Forest Service and operates from the National Weather Service Forecast Office in Seattle. NWAC services are made possible by important collaboration and support from a wide variety of federal, state and private cooperators.

The 5000’ temperature forecast does not imply a trend over the 12 hr period and only represents the max and min temperatures within a 12 hr period in the zone. The 6-hr snow level forecast, the forecast discussion, and weather forecast sections may add detail regarding temperature trends.

The snow level forecast represents the general snow level over a 6 hr time period. Freezing levels are forecast when precipitation is not expected.

*Easterly or offshore flow is highlighted with an asterisk when we expect relatively cool east winds in the major Cascade Passes. Easterly flow will often lead to temperature inversions and is a key variable for forecasting precipitation type in the Cascade Passes. Strong easterly flow events can affect terrain on a more regional scale.

Ridgeline winds are the average wind speed and direction over a 6 hr time period.

The wind forecast represents an elevation range instead of a single elevation slice. The elevation range overlaps with the near and above treeline elevation bands in the avalanche forecast and differs per zone.

Wind direction indicates the direction the wind originates or comes from on the 16-point compass rose.

Water Equivalent (WE) is the liquid water equivalent of all precipitation types; rain, snow, ice pellets, etc., forecast to the hundredth of an inch at specific locations. To use WE as a proxy for snowfall amounts, start with a snow to water ratio of 10:1 (10 inches of snow = 1 inch WE). Temperatures at or near freezing will generally have a lower ratio (heavy wet snow) and very cold temperatures can have a much higher ratio (dry fluffy snow).

The label LT, is shorthand for ‘less than’.